Black Gold

The one energy related issue I have not previously discussed is petroleum, gasoline, oil, black gold. Whatever you want to call it, it is the the main source of the problems we face today. Our economy is driven by oil (no pun intended). As reserves dwindle, we find ourselves on a slippery slope. Do we look the other way? Do we put time and resources into research? I have discussed the possible alternative energy sources. Now it's time to hit the crux of the matter.

As with the other fossil fuels, it is good to discuss the origins of oil. There are several conditions that need to be perfect or nearly perfect for oil to form:

1. Basins at the edges of the oceans must have a high concentration of organic material (5% or over) in their sedimentary rock. These conditions are extremely rare. If it weren't, there would be a lot more oil than there is currently.

2. The sediments have to be withing the oil window, 7500-15000ft. At 7500ft, the temperature causes large organic molecules to break down. Molecules with 5-20 carbon atoms are liquid at room temperature and pressure. Any less than 5 and the molecule is a gas at room temp and pressure.

3. Organic rick sediment buried below 15000ft will be "dry" natural gas, not oil.

4. About 90% of the oil finds its way to the surface via oil seeps. Only 10% gets trapped underground.

5. Porous rocks such as sandstone, limestone (CaCO3), and dolomite (CaMg(CO3)2) must be present to serve as reservoirs.

6. The pores in the host rock must be connected to each other, allowing for oil flow (permeability). The larger the pores in the rock, the more permeable it is. That being said, the permeability is the square of the grain size. Increasing the grain by 2 increases permeability by 4. And so on.

7. There must be a layer of rock above the oil reservoir that is relatively leak-proof. A few examples of such cap-stone rock types are fine-grained mudstone, halite (NaCl), and anhydrite (CaSO4).

Without even one of these factors, there will be no oil. The Middle East is prime oil country as the conditions there are just near perfect. As it stands, Saudi Arabia is the largest producer of oil in the world (7.7 million barrels/day with only 1600 working wells). The next largest produces are Russia (7.4 mil barrels/day, 41000 wells) and the United States (5.8 mil barrels/day, 521,000 wells).

In the past, oil drilling was done by "banging a chisel up and down on the end of a rope." Eventually, drills were developed which operated using a heavy bit of wire with a drill bit attached to it. A thin mud flows back and forth in the drill pipe. However, other methods have been developed.

If you recall, a recent commercial depicted a "man with a problem." In one of the commercials, he was sitting in a shop with his son when the boy bent his straw to get the last bit of his drink from the bottom and sides of his glass. I'm sorry to say, but horizontal drilling is not a new invention. It has been around for years. But it is effective. It can turn a vertical well into a horizontal well. This can be effective for up to a half mile or more. "Diamond bits" are tungsten-carbide drill heads in which synthetic diamonds are embedded. The hardness of the diamond allows drilling to be done much more quickly, and can drill up to 7000ft. It saves costs, too, since the drilling doesn't have to stop to replace worn our drill bits.

Recently Boeing Corporation donated several powerful lasers to the Colorado School of Mines. This was done in hopes of finding even faster drilling methods. (It should be noted the lasers were from the abandoned Star Wars program.) Finally, some rigs use continuous drilling, unrolling pipe like fishing line.

When the oil well is initially breached, the oil and gas comes bubbling up because the pressure is not equal. However, it eventually dies down and pumpjacks are set up to bring the oil to the surface. Once the easily accessible oil is retrieved, secondary recovery is started. Early on, this was accomplished by flooding the well with water so that the lighter oil could be recovered. Unfortunately, most efforts only recovered about half of the available oil in the reservoir. But other methods have been developed. Carbon dioxide is one especially good method. It is extremely soluble in crude oil and it gets the oil moving again. The drawback? 100% of the reservoir oil isn't recoverable no matter what we do.

We can't forget the rising price of oil, either. As oil becomes more scarce, the price rises to balance drilling and exploration costs against consumer demand. The Organization of the Petroleum Exporting Countries (OPEC) was formed, in part, to help regulate the price of oil. OPEC no longer controls the price of oil. But, then, no one does.

Most oil is used for transportation (a fact mentioned in previous posts). But something needs to be done. Technology that doesn't rely on oil. Better city planning. More people carpooling or using public transportation. Thoughts?